Re: Can I use CRoaring library in Git?

[Abhradeep Chakraborty <chakrabortyabhradeep79@gmail.com>]

On Mon, Jul 18, 2022 at 4:43 PM Jakub Narębski <jnareb@gmail.com> wrote:
>
> Abhradeep Chakraborty <chakrabortyabhradeep79@gmail.com> writes:
>
> > Hello,
> >
> > I need the CRoaring[1] library to use roaring bitmaps. But it has
> > Apache license v2 which is not compatible with GPLv2[2].
>
> Actually Apache License v2.0 *is* compatibile with GPLv2 and GPLv3
> in the sense that you can include the Apache licensed code (like the
> CRoaring library) in the GPLv2 project (like Git).
>
> Quote from the cited "Apache License V2.0 and GPL Compatibility"[2]:
>
>   The Free Software Foundation considers the Apache License, Version 2.0
>   to be a free software license, compatible with version 3 of the GPL.
>   The Software Freedom Law Center provides practical advice for
>   developers about including permissively licensed source.
>
>   Apache 2 software can therefore be included in GPLv3 projects, because
>   the GPLv3 license accepts our software into GPLv3 works. However,
>   GPLv3 software cannot be included in Apache projects. The licenses are
>   incompatible in one direction only, and it is a result of ASF's
>   licensing philosophy and the GPLv3 authors' interpretation of
>   copyright law.

But the same article also says  -

  Despite our best efforts, the FSF has never considered the Apache License
  to be compatible with GPL version 2, citing the patent termination
and indemnification
  provisions as restrictions not present in the older GPL license. The
Apache Software
  Foundation believes that you should always try to obey the
constraints expressed by
  the copyright holder when redistributing their work.